As a conventionally proposed indoor base isolation floor structure of a building and the like, as shown in Patent Literature 1, for example, there has been proposed a base isolation floor in which a plurality of ball bearings are fixed to a frame to thereby make the flame movable on a floor slab. In the technique disclosed by the Patent Literature 1, the ball bearings are arranged particularly in a lower portion of a metal pipe, whereby even if an earthquake load acts, since the rolling friction resistance of the ball bearing is small, the vibration is hardly transmitted to the base isolation floor.
Further, as disclosed in Patent Literature 2, there has been proposed a base isolation floor in which an upper plate and a lower plate provided with a plurality of grooves are installed between a floor material and precision equipment and the like, and balls in the grooves are rotated to make the upper plate movable on the lower plate. In the technique disclosed by the Patent Literature 2, even if the earthquake load acts, since the rolling friction resistance of the balls in the grooves is small, the vibration is hardly transmitted to the precision equipment and the like on the upper plate.